1. Field of the Invention
This invention relates to an instrument for high-frequency treatment and a method of high-frequency treatment by utilizing high-frequency energy. More particularly, the invention relates to an instrument for high-frequency treatment and a method of high-frequency treatment useful for surgical operations using an endoscope.
2. Description of the Related Art
A treating instrument for surgical operations using an endoscope can be an instrument for high-frequency treatment that cuts or coagulates living body tissues by using high frequencies. This kind of instrument for high-frequency treatment is equipped with a pair of jaws each of which is provided with an electrode for feeding a high-frequency current. The pair of jaws holding the living body tissue for effecting a desired treatment with high-frequency energy are called bipolar forceps. Bipolar forceps have heretofore been used for arresting the bleeding of blood vessels and for closing Fallopian tubes, i.e., for coagulating living body tissue that is to be treated or for cutting living body tissue that has been coagulated.
A conventional bipolar forceps have been disclosed in JP-A-10-199. This bipolar forceps include a first electrode member that turns about an axis and a second electrode member opposed thereto. The first electrode member has, separately from each other, a cutting electrode surface with a cutting edge formed on the peripheral surface about the axis thereof and a coagulating electrode surface having a wide area. To use the bipolar forceps, either the cutting electrode surface or the coagulating electrode surface is selected by turning the first electrode member about its axis so as to direct the selected electrode surface to the second electrode. Therefore, either one of the electrode surfaces to be used must be selected depending upon whether tissue is to be cut or coagulated.
As bipolar forceps of another type, there has also been known bipolar forceps in which the tissue-holding portion of the pair of jaws is divided into a front region and a rear region, i.e., into a cutting portion for cutting the tissue and a holding portion for coagulating the tissue. In the bipolar forceps of this type, the cutting and the coagulation are effected separately at different places of the jaws.
The former bipolar forceps are capable of effecting both treatments, i.e., cutting and coagulation without changing the instrument. Depending upon cutting the tissue or coagulating the tissue, however, skill is necessary for changing the direction by turning the first electrode member about its axis.
In the latter bipolar forceps, the part for cutting the tissue and the part for coagulating the tissue are separated functionally and completely. Therefore, depending upon whether tissue is to be cut or coagulated, the operation for holding the tissue must be effected again.
The conventional bipolar forceps are capable of executing both of cutting and coagulation treatments. When the tissue is to be coagulated, however, the tissue must be held by the pair of electrode members, and a high-frequency current must be fed into the held tissue. Therefore, the held tissue could be coagulated only locally.